Metallocorroles with Formally Tetravalent Iron

The unusual oxidation state + IV for iron centers can be stabilized by porphyrin‐like corrole ligands in such a way that the compounds 1 (R Cl, Ph, OFe‐corrole) can be isolated at room temperature. The oxygen‐bridged binuclear iron( IV ) corrole, which can be readily converted into the mononuclear iron( IV ) corrole, forms as the only defined product from the reaction of the ligand with [Fe 2 (CO) 9 ] followed by workup in air. In contrast, only a few iron( IV ) porphyrins are known so far, and these are too unstable to be isolated as solids.